Fungicidal coating composition containing thianaphthene carboxylic acid salt



FUNGICIDAL COATING COMPOSITION CON- TAINING THIANAPHTHENE CARBOXYLIC ACID SALT Otto C. Elmer, Fishlrill, and Edward R. Christensen, Beacon, N. Y., assignors to The Texas Company, New York, N. Y., a corporation of Delaware No Drawing. Application December 20, 1952, Serial No. 327,170

4 Claims. (Cl. 167-33) This invention relates to novel fungicidal compositions which can be used both in aqueous and organic solvents, but are particularly useful in coating compositions such as paints and asphalts.

The novel fungicidal compositions of this invention comprise an aqueous or hydrocarbon mixture of groups I or II metal salts of thianaphthene carboxylic acid. The group I metal salts of thianaphthene carboxylic acid are particularly adapted for use in a water vehicle in which they are soluble to the extent of about 40 percent. The group II metal salts of thianaphthene carboxylic acid are usually employed in an oil vehicle. The water or hydrocarbon carrier comprises a major portion of the fungicidal composition; the thianaphthene carboxylic acid salts constitute 0.1 to percent of the total composition and the remainder comprises carrier and modifying agents. Compounds such as fatty acid soaps and synthetic detergents are useful adjuvants for the novel fungicidal compositions of this invention since they have a synergistic effect on the fungicidal action of the compositions of this invention in addition to assuring a uniform distribution of the thianaphthene carboxylic acid salts throughout the water or oil vehicle.

Metal salts of thianaphthene carboxylic acid are simply prepared by reaction of the acid with metal inorganic hydroxides or basic salts such as carbonates. The metal salts of thianaphthene carboxylic acid are represented by the following formula wherein X represents a group I metal and Y represents a group II metal:

OOOYOOC S ]COOX S [S The novel fungicidal compositions of this invention are effective against a wide variety of fungi, are ther mally stable and do not exhibit objectionable odor. Another advantageous attribute of the fungicidal compositions of this invention is their wide application because of the high potency of both the water and oil base formulations.

The activity of the fungicides of this invention was determined against a mixture of fungi which is commonly designated the JAN mixture, since it is prescribed in joint Army-Navy specifications as the test organisms for evaluating fungus-resistant varnish. The JAN mixture comprises the following organisms: Aspergillus niger, Aspargillus flavus, Penicillium luteum and Trichoderma T-l. The test procedure followed in determining the activity of the novel fungicides of this invention comprises the following steps: an agar substrate containing the fungicide was placed in a Petri dish and sterilized; after cooling, the Petri dish was inoculated in the center of the dish with a small mycelial transplant or spore suspension of the JAN fungi; three to five replicates of each test material were prepared and the radial growth of the fungi in the test and control dishes was measured at regular intervals; after a week, the distance of radial growth was plotted as a function of time and there were obtained straight lines of different slope for the test and control dishes. The degree of inhibition is determined as the ratio of the difference between the radial growth in the control dish and the radial growth in the test dish to the radial growth in the control dish for the same time interval. The procedure places the test on a quantitative basis and provides a scale for comparison of results between dilferent tests.

In the following table, the results of quantitative fungitoxicity tests made in accordance with the above-outlined procedure are demonstrated with the zinc, lead and copper salts of a mixture of 2- and B-thianaphthene carboxylic acids. The superiority of the thianaphthene carboxylic acid salts as fungicides is demonstrated by comparison with several commercially available fungicides; Vancide is an aqueous solution of the salts of mercaptobenzothiazole and dimethyldithiocarbamic acid; Dowicide is tetrachlorophenol.

The fungicidal compositions of this invention are prepared from 2- or B-thianaphthene carboxylic acid. Since mixtures of 2- and 3-acids are often obtained in the synthetic methods employed in the manufacture of thianaphthene carboxylic acid, mixtures of the 2- and 3-isomers are most often utilized in the preparation of the salts employed in the fungicidal compositions of the invention.

In addition to possessing the superior fungicidal activity demonstrated in the previous table, thianaphthene carboxylic acid salts of groups I and II metals possess exceptional thermal stability and do not show objectionable odors at temperatures up to about 450 F. The use of fungicidal compositions in coating compositions such as paints and asphalts and in clothing and cellulose fiber materials used in tropical climates requires that fungicidal compositions possess high thermal stability. The novel compositions of this invention containing thianaphthene carboxylic acid salts as the major active constituent fill this requirement in excellent fashion since they are free from odors even at temperatures in the neighborhood of 450 F. and up.

Asphalt shingles possessing exceptional resistance to fungi are prepared by dipping roofing felt into asphalt shingle saturant into which a group II metal salt of thianaphthene carboxylic acid has been incorporated. The zinc salt is particularly active in imparting fungitoxic properties to asphalt shingles.

The procedure employed for the manufacture of the asphalt shingles is briefly outlined as follows: the zinc salt of a mixture of 2- and S-thianaphthene carboxylic acids is added to asphalt shingle saturant at a temperature of about 450 F. in an amount equivalent to l percent concentration of fungicide in the asphalt saturant. Because of the exceptional thermal stability of the zinc salt of thianaphthene carboxylic acid, no decomposition of the fungicide is observed and the asphalt shingle saturant and the salt appear to be compatible; a strip of roofing felt is then dipped into the shingle saturantcontaining zinc thianaphthene carboxylate to form the highly fungicidal asphalt shingle.

The fungus resistance of asphalt shingles prepared in this fashion is indicated by the following comparative test:

A sample of theasphalt prepared as outlined above is sterilized in a Petri dish inoculated with 1 cc. of a spore suspension of the I AN fungi and incubated. After seven days of incubation, no fungal growth is observed in the shingle prepared with shingle saturant containing the zinc thianaphthene carboxylic acid salt; a control sample showed fungusgrowth on the asphalt usrface and on the exposed felt edge. Asphalt shingles prepared with asphalt shingle saturants containing other group 11 metal salts of thianaphthene carboxylic acid are also resistant to reaction of fungi.

The thianaphthene carboxylic acid salts of groups I and II metals may be incorporated in the different compositions in amounts equivalent to 0.1 to 10 percent of the total composition, but usually constitute 0.1 to 2 percent of the total composition. The exceptional potency of the thianaphthene carboxylic acid salts permits their employment in small concentrations without impairing the fungicidal activity of the resulting composition.

The incorporation of 0.1 to 1 percent of the sodium salts of thianaphthene carboxylic acid in soaps or synthetic detergents makes very effective fungicidal compositions which are useful in treating fungal skin infections and in Washing textiles subject to fungal attack. The sodium salt is simply incorporated in the soap or synthetic detergent during its manufacture because of its water solubility.

In general, soaps and synthetic detergents exert a synergistic effect on the action of the thianaphthene carboxylic acid salts. Accordingly, superior fungicidal compositions comprise a water or hydrocarbon carrier, 0.1 to 2 percent thianaphthene carboxylic acid salt and 1 to 10 percent of an alkali metal or alkaline earth metal salt of a fatty acid, alkaryl sulfonate or alkyl sulfate. Sodium oleate and sodium stearate are examplesof fatty acid salts which exert this synergistic action; alkyl benzene sulfonate salts cotuaining an alkyl group containing 9 to 18 carbon atoms are examples of alkaryl sulfonate salts having this synergistic action; sodium lauryl sulfate and sodium decyl sulfate exemplify alkyl sulfate salts possessing this property.

Fungi-resistant paints are prepared by adding 0.1 to 2 percent of Zinc thianaphthene carboxylate to a paint composition; the zinc thianaphthene carboxylate is ordinarily dissolved in the paint thinner and the resulting solution added to the paint.

A kerosene mixture containing 0.1 to 2 percent copper or zinc salts of thianaphthene carboxylic acid serves as an excellent fungicidal spray, and can be used for coating Wood products to preserve them against fungal attack. Zinc or copper thianaphthene carboxylate can also be dissolved in liquefied gases such as Freon and the resulting pressurized solutions used as fungicidal aerosols.

Obviously, many modifications and variations of the invention as hereinbefore set forth may be made Without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. Fungicidal compositions comprising a liquid carrier in which is incorporated 0.1 to 10 percent of a metal salt of thianaphthene carboxylic acid selected from the group consisting of the copper, zinc, lead, and sodium salts.

2. The fungicidal compositions of claim 1 wherein the carrier comprises 98 to 99.9 percent and the thianaphthene carboxylic acid salt comprises 0.1 to 2 percent of the total composition.

3. Fungicidal compositions comprising a liquid carrier, 0.1 to 10 percent of a metal salt of thianaphthene carboxylic acid selected from the group consisting of the copper, zinc, lead, and sodium salts, and 1 to 10 percent of a detergent selected from the group consisting of alkali metal and alkaline earth metal salts of fatty acids, of alkaryl sulfonates, and of alkyl sulfates.

4. The fungicidal compositions of claim 3 wherein the thianaphthene carboxylic acid salt constitutes 0.1 to 2 percent of the total composition.

cides, 2d edition 1948, pages 189 to 195, 211, 223, to 226, 225 to 256 and 284 to 286. 

3. FUNGICIDAL COMPOSITIONS COMPRISING A LIQUID CARRIER, 0.1 TO 10 PERCENT OF A METAL SALT OF THIANAPHTHENE CARBOXYLIC ACID SELECTED FORM THE GROUP CONSISTING OF THE COPPER, ZINC, LEAD, AND SODIUM SALTS, AND 1 TO 10 PERCENT OF A DETERGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND ALKALINE EARTH METAL SALTS OF FATTY ACIDS, OF ALKARYL SULFONATES, AND OF ALKYL SULFATES. 